Molecular cloning of the Corynebacterium glutamicum ('Brevibacterium lactofermentum' AJ12036) odhA gene encoding a novel type of 2-oxoglutarate dehydrogenase

Microbiology (Reading). 1996 Dec;142 ( Pt 12):3347-54. doi: 10.1099/13500872-142-12-3347.

Abstract

The Corynebacterium glutamicum ('Brevibacterium lactofermentum' AJ12036) odhA gene, encoding 2-oxoglutarate dehydrogenase (E1o subunit of the 2-oxoglutarate dehydrogenase complex), has been isolated and identified as an homologous counterpart of the Escherichia coll sucA and Bacillus subtilis odhA genes. The nucleotide sequence of a 4394 bp chromosomal fragment containing the C. glutamicum odhA gene was determined. The odhA gene comprised 3771 bp (1257 codons, including the initiation codon) and a molecular mass of 138656 Da was predicted for the OdhA polypeptide. Northern blot analysis revealed a 3.9 kb transcript. The size of the transcript, together with the presence of a rho-independent terminator-like structure, suggests that C. glutamicum odhA is monocistronic. Cells harbouring plasmids carrying C. glutamicum odhA showed a threefold increase in specific 2-oxoglutarate dehydrogenase complex activity and expression of a protein with an apparent molecular mass of 136 kDa, in good agreement with the predicted size of the OdhA polypeptide. The C-terminal region of the C. glutamicum OdhA protein shows strong sequence similarity to E1os from other organisms. C. glutamicum OdhA has an N-terminal extension not found in previously reported E1os. The amino acid sequence of this extension shows similarity to that of the C-terminal region of dihydrolipoamide S-succinyltransferase (E2o) subunits of 2-oxoglutarate dehydrogenase complexes and dihydrolipoamide S-acetyltransferase (E2p) subunits of pyruvate dehydrogenase complexes. It suggests that the C. glutamicum odhA gene might encode a novel bifunctional protein with E1o and E2o activities.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Bacillus subtilis / enzymology
  • Base Sequence
  • Chromosomes, Bacterial
  • Cloning, Molecular
  • Codon
  • Corynebacterium / enzymology*
  • Corynebacterium / genetics*
  • Genes, Bacterial*
  • Ketoglutarate Dehydrogenase Complex / biosynthesis*
  • Ketoglutarate Dehydrogenase Complex / chemistry
  • Ketoglutarate Dehydrogenase Complex / genetics
  • Macromolecular Substances
  • Molecular Sequence Data
  • Pyruvate Dehydrogenase Complex / chemistry
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / chemistry
  • Restriction Mapping
  • Sequence Homology, Amino Acid

Substances

  • Codon
  • Macromolecular Substances
  • Pyruvate Dehydrogenase Complex
  • Recombinant Proteins
  • Ketoglutarate Dehydrogenase Complex

Associated data

  • GENBANK/D84102